Answer:
1) Mass that needs to be converted at 100% efficiency is 0.3504 kg
2) Mass that needs to be converted at 30% efficiency is 1.168 kg
Step-by-step explanation:
By the principle of mass energy equivalence we have

where,
'E' is the energy produced
'm' is the mass consumed
'c' is the velocity of light in free space
Now the energy produced by the reactor in 1 year equals

Thus the mass that is covertred at 100% efficiency is

Part 2)
At 30% efficiency the mass converted equals
